Clean drinking water for the world

Scales says the world is heading for a water crisis. Some rivers are so polluted they can’t even be used for irrigation. Cities are pumping dry their underground water reserves. Climate change is altering rainfall. There are more and more chemicals in water supplies – and the effects on human health are sometimes unclear.

The solution, he says, is cheap, safe technology which can recycle dirty water – including sewage – into drinking water.

“The fact that people haven’t got the ability to take dirty water and turn it into clean water is a real problem in the world,” says Scales, who leads the water theme at the University of Melbourne’s Carlton Connect sustainability and innovation precinct. “Recycling gives you a lot more resilience in your water supply.”

Scales has been working on new, optimal system to recycle wastewater. He hopes it can be used in Asia, particularly China, India and South-East Asia, where some aquifers are dangerously low.

The technology is also suited to Australia’s inland cities and towns. Major coastal cities have been drought-proofed by desalination plants but that’s not an option for towns like Orange, Bathurst and Bendigo. “How would they go in the next big drought? The answer is they’re not as resilient,” Scales says.

Drinking recycled sewage has been controversial in Australia. “I’m not saying that’s an easy social thing to manage,” Scales says, but notes the next drought will come eventually.

“Recycling gives you a lot more resilience in your water supply.”

Nationally, Scales has mapped out how Australia can better manage its notoriously variable water resources in a blueprint for Carlton Connect. The blueprint calls for smarter use of technology and markets, and more focus on sustainability.

It’s a natural fit for this self-described “farm boy” from country Victoria. “I grew up on a farm near Bendigo, I’m interested in water, I’m interested in country.”

Scales’ new water recycling system is being tested in a pilot plant. The plant takes existing technology and rearranges it into a sequence of seven stages, including ozonation, microfiltration, UV and chlorination. While other plants strip out pathogens (bugs) first, then chemicals, this plant removes the chemicals early. “We’re doing it the other way round,” Scales says. He’s also prioritised keeping costs down.

Scales, an academic in chemical and biomolecular engineering, says while wastewater systems are good at removing pathogens, chemicals should be a priority. Water can contain pharmaceuticals, antibiotics, hormones, industrial chemicals, chemicals like Bisphenol A from plastics – and some pass straight through treatment plants.

The plant, in Hobart, will be tested throughout 2015 then installed in a town of 150 people. Scales runs the plant via his laptop in Beijing. He says cities and towns will start needing this technology in 10 to 20 years, as climate change affects water supply. “We’ll be ready.”

“I get a real buzz out of doing practical problems and getting into them, and finding out there’s some really fundamental research in them that people haven’t done,” Scales says. Would he drink water from the plant? “Yeah, no problems.”

So why is Scales in Beijing? Melbourne University has a joint research centre with China on river basins, and joint classes and e-subjects are run with students at Beijing’s Tsinghua University. Scales has partnerships with 10 groups in China, including the Chinese Academy of Science. About 50 people are involved. He travels to China regularly.

Next is India; Scales plans to get involved in the high-profile project to clean-up the Ganges river.